The pipes to the heat exchanger in this Firebird Olympic combi boiler
have joints of a type I am not used to. The pipe ends have a flat
flange which fits against a male threaded brass tube like the tail of
a tap[1], but unlike a tap connector they have no continuation of the
pipe into the tail. They have been made with various versions of fibre
washer and jointing compound, but invariably start leaking. I suspect
they may be designed to be used without any washer, but the flanges do
not lie flat because the copper pipes are not accurately made to lie in
the plane of the joints on the heat exchanger. I feel the copper
flanges might bend or break if tightened with no washer.

Does anyone know how these joints should be made, and how to stop them
leaking? Many thanks for any comments.


[1] http://www.inchoate.org/union.jpg





--
Percy Picacity

"Percy Picacity" wrote in message
...
The pipes to the heat exchanger in this Firebird Olympic combi boiler
have joints of a type I am not used to. The pipe ends have a flat
flange which fits against a male threaded brass tube like the tail of
a tap[1], but unlike a tap connector they have no continuation of the
pipe into the tail. They have been made with various versions of fibre
washer and jointing compound, but invariably start leaking. I suspect
they may be designed to be used without any washer, but the flanges do
not lie flat because the copper pipes are not accurately made to lie in
the plane of the joints on the heat exchanger. I feel the copper
flanges might bend or break if tightened with no washer.

Does anyone know how these joints should be made, and how to stop them
leaking? Many thanks for any comments.


[1] http://www.inchoate.org/union.jpg





--
Percy Picacity

Cracking drawing Percy ! I can see straight away why it leaks. The union nut
is much too big for the thread ... :-)

Sorry, couldn't resist that !

Arfa

"Arfa Daily" wrote in
:

"Percy Picacity" wrote in message
...
The pipes to the heat exchanger in this Firebird Olympic combi
boiler have joints of a type I am not used to. The pipe ends
have a flat flange which fits against a male threaded brass tube
like the tail of a tap[1], but unlike a tap connector they have
no continuation of the pipe into the tail. They have been made
with various versions of fibre washer and jointing compound, but
invariably start leaking. I suspect they may be designed to be
used without any washer, but the flanges do not lie flat because
the copper pipes are not accurately made to lie in the plane of
the joints on the heat exchanger. I feel the copper flanges
might bend or break if tightened with no washer.

Does anyone know how these joints should be made, and how to stop
them leaking? Many thanks for any comments.


[1] http://www.inchoate.org/union.jpg





--
Percy Picacity

Cracking drawing Percy ! I can see straight away why it leaks. The
union nut is much too big for the thread ... :-)

Sorry, couldn't resist that !

Arfa

Thanks - drawing was never my strong point!


--
Percy Picacity

In article ,
Percy Picacity wrote:
he pipes to the heat exchanger in this Firebird Olympic combi boiler
have joints of a type I am not used to. The pipe ends have a flat
flange which fits against a male threaded brass tube like the tail of
a tap[1], but unlike a tap connector they have no continuation of the
pipe into the tail. They have been made with various versions of fibre
washer and jointing compound, but invariably start leaking. I suspect
they may be designed to be used without any washer, but the flanges do
not lie flat because the copper pipes are not accurately made to lie in
the plane of the joints on the heat exchanger. I feel the copper
flanges might bend or break if tightened with no washer.

Does anyone know how these joints should be made, and how to stop them
leaking? Many thanks for any comments.

That's similar to brake pipe unions on cars. Called flared. On brake pipes
it has no washer or jointing compound. And has to withstand far higher
temperature and pressure. Of course like all such things has to be made
correctly.

I'd be inclined to just clean everything and use some Fernox LS-X jointing
silicone.

Might also be worth running a fine file across the heat exchanger mating
face to make sure it's true and flat.

--
*My dog can lick anyone

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in
:

In article ,
Percy Picacity wrote:
he pipes to the heat exchanger in this Firebird Olympic combi
boiler have joints of a type I am not used to. The pipe ends
have a flat flange which fits against a male threaded brass tube
like the tail of a tap[1], but unlike a tap connector they have
no continuation of the pipe into the tail. They have been made
with various versions of fibre washer and jointing compound, but
invariably start leaking. I suspect they may be designed to be
used without any washer, but the flanges do not lie flat because
the copper pipes are not accurately made to lie in the plane of
the joints on the heat exchanger. I feel the copper flanges
might bend or break if tightened with no washer.

Does anyone know how these joints should be made, and how to stop
them leaking? Many thanks for any comments.

That's similar to brake pipe unions on cars. Called flared. On
brake pipes it has no washer or jointing compound. And has to
withstand far higher temperature and pressure. Of course like all
such things has to be made correctly.

I'd be inclined to just clean everything and use some Fernox LS-X
jointing silicone.

Might also be worth running a fine file across the heat exchanger
mating face to make sure it's true and flat.

That was my immediate idea, but the fact the pipes don't lie in the
same plane, and would be significantly twisted to lie flat on the
joints is a bit worrying. this could be because some of them have
been bent, or perhaps imprecise manufacture. Perhaps I'll give this
a go next time one fails. The last (15mm) one I used a rubber
washer with filter from a washing machine hose, will be interesting
to see if this works for a long time. If it does, I need a source
of similarly rigidified (by the filter) 22mm ones.


--
Percy Picacity

"Percy Picacity" wrote in message
...
The pipes to the heat exchanger in this Firebird Olympic combi boiler
have joints of a type I am not used to. The pipe ends have a flat
flange which fits against a male threaded brass tube like the tail of
a tap[1], but unlike a tap connector they have no continuation of the
pipe into the tail. They have been made with various versions of fibre
washer and jointing compound, but invariably start leaking. I suspect
they may be designed to be used without any washer, but the flanges do
not lie flat because the copper pipes are not accurately made to lie in
the plane of the joints on the heat exchanger. I feel the copper
flanges might bend or break if tightened with no washer.

Does anyone know how these joints should be made, and how to stop them
leaking? Many thanks for any comments.

That type of joint (not uncommon) certainly requires a washer between the
faces.

Could be the wrong type has been used.
The tap connector type are too narrow, also may not have been tightened
correctly.

Also check that the flange face is not cracked and letting water by.

In article ,
Percy Picacity wrote:
That was my immediate idea, but the fact the pipes don't lie in the
same plane, and would be significantly twisted to lie flat on the
joints is a bit worrying. this could be because some of them have
been bent, or perhaps imprecise manufacture.

Then they need to be bent to fit. Use a bending spring and perhaps some
heat.

--
*Do they ever shut up on your planet?

Dave Plowman London SW
To e-mail, change noise into sound.

"Heliotrope Smith" wrote in
:


"Percy Picacity" wrote in message
...
The pipes to the heat exchanger in this Firebird Olympic combi
boiler have joints of a type I am not used to. The pipe ends
have a flat flange which fits against a male threaded brass tube
like the tail of a tap[1], but unlike a tap connector they have
no continuation of the pipe into the tail. They have been made
with various versions of fibre washer and jointing compound, but
invariably start leaking. I suspect they may be designed to be
used without any washer, but the flanges do not lie flat because
the copper pipes are not accurately made to lie in the plane of
the joints on the heat exchanger. I feel the copper flanges
might bend or break if tightened with no washer.

Does anyone know how these joints should be made, and how to stop
them leaking? Many thanks for any comments.

That type of joint (not uncommon) certainly requires a washer
between the faces.

Could be the wrong type has been used.
The tap connector type are too narrow, also may not have been
tightened correctly.

Also check that the flange face is not cracked and letting water
by.


Thanks, any suggestions as to what the suitable washers are called
and where I might get some? Are they likely to be fibre or rubber?

Thanks for any advice!

--
Percy Picacity

"Dave Plowman (News)" wrote in
:

In article ,
Percy Picacity wrote:
That was my immediate idea, but the fact the pipes don't lie in
the same plane, and would be significantly twisted to lie flat on
the joints is a bit worrying. this could be because some of them
have been bent, or perhaps imprecise manufacture.

Then they need to be bent to fit. Use a bending spring and perhaps
some heat.

That's not easy as they are very short pipes, and one has a side branch
brazed on near the end, which branch is too near a bend to use a tee, I
presume. But I may get better results if I loosen the joints at the
other ends of the pipes (ordinary compression), before refixing the
heat exchanger. I want to redo the whole thing when I have firm ideas
as to whether to use washers and what type.


--
Percy Picacity

On 29 Aug, 23:28, Percy Picacity wrote:
"Dave Plowman (News)" wrote :

In article ,
* *Percy Picacity wrote:
That was my immediate idea, but the fact the pipes don't lie in
the same plane, and would be significantly twisted to lie flat on
the joints is a bit worrying. *this could be because some of them
have been bent, or perhaps imprecise manufacture.

Then they need to be bent to fit. Use a bending spring and perhaps
some heat.

That's not easy as they are very short pipes, and one has a side branch
brazed on near the end, which branch is too near a bend to use a tee, I
presume. *But I may get better results if I loosen the joints at the
other ends of the pipes (ordinary compression), before refixing the
heat exchanger. *I want to redo the whole thing when I have firm ideas
as to whether to use washers and what type.

--
Percy Picacity

You can buy a Regin fibre washer pack with a couple of 1/2" 3/4" and
1" flat washers for a couple of quid. Clean the metal joint surfaces
thoroughly and if the threads are scaled wire brush them and put some
silicon grease on the threads and the inside of the union nuts so they
will tighten without overstressing the things.
The pipe ends should lie flat on the protruding threaded part of the
heat exchanger. If they don't you should loosen the other ends of the
sections so they will. When the Heat exchanger is tightened then
retighten the other ends and all should be fine. It is wise to keep an
eye on these joints and nip up if required before any weep develops
into a leak. The Firebird Combi is a decent unit but the heat
exchanger requires monitoring. In hard water areas it sometimes
pinholes between the domestic and the sealed system side, however this
is not a regular event by any means.

John

cynic wrote in
news:b575265a-b2c0-41db-b7d9-

m:




You can buy a Regin fibre washer pack with a couple of 1/2" 3/4"
and 1" flat washers for a couple of quid. Clean the metal joint
surfaces thoroughly and if the threads are scaled wire brush them
and put some silicon grease on the threads and the inside of the
union nuts so they will tighten without overstressing the things.
The pipe ends should lie flat on the protruding threaded part of
the heat exchanger. If they don't you should loosen the other ends
of the sections so they will. When the Heat exchanger is tightened
then retighten the other ends and all should be fine. It is wise
to keep an eye on these joints and nip up if required before any
weep develops into a leak.

Very helpful, thanks.


The Firebird Combi is a decent unit but
the heat exchanger requires monitoring. In hard water areas it
sometimes pinholes between the domestic and the sealed system
side, however this is not a regular event by any means.

John


That's interesting, because I've got a slow leak somewhere. I
suspect the boiler was put together by an amateur (FSVO) because
pretty well every joint on it and the central heating circuit has
leaked at some point since I moved in. I presume the only way to
test it is to disconnect the hot water side and wait a long time, or
is it better to take it off and pressurise it in some way? I'll have
to check that when I redo it. It's a soft water area, however.

--
Percy Picacity

On Aug 29, 9:32*pm, Percy Picacity wrote:
"Heliotrope Smith" wrote :
"Percy Picacity" wrote in message
.. .
The pipes to the heat exchanger in this Firebird Olympic combi
boiler have joints of a type I am not used to. *The pipe ends
have a flat flange which *fits against a male threaded brass tube
like the tail of a tap[1], but unlike a tap connector they have
no continuation of the pipe into the tail. *They have been made
with various versions of fibre washer and jointing compound, but
invariably start leaking. *I suspect they may be designed to be
used without any washer, but the flanges do not lie flat because
the copper pipes are not accurately made to lie in the plane of
the joints on the heat exchanger. *I feel the copper flanges
might bend or break if tightened with no washer.

Does anyone know how these joints should be made, and how to stop
them leaking? *Many thanks for any comments.

That type of joint (not uncommon) certainly requires a washer
between the faces.

Could be the wrong type has been used.
The tap connector type are *too narrow, also may not have been
tightened correctly.

Also check that the flange face is not cracked and letting water
by.

Thanks, any suggestions as to what the suitable washers are called
and where I might get some? *Are they likely to be fibre or rubber?

Thanks for any advice!


On such joints in other locations I've seen fibre. I had one joint on
high pressure water that repeatedly leaked after replacing the fibre
washer, so I decided to try a rubber one, with doubt, but it worked
great and fixed the problem.

I cant help wondering if brazing would be a good option here.


NT

Percy Picacity wrote in
:

cynic wrote in
news:b575265a-b2c0-41db-b7d9-

m:




You can buy a Regin fibre washer pack with a couple of 1/2" 3/4"
and 1" flat washers for a couple of quid. Clean the metal joint
surfaces thoroughly and if the threads are scaled wire brush them
and put some silicon grease on the threads and the inside of the
union nuts so they will tighten without overstressing the things.
The pipe ends should lie flat on the protruding threaded part of
the heat exchanger. If they don't you should loosen the other
ends
of the sections so they will. When the Heat exchanger is
tightened
then retighten the other ends and all should be fine. It is wise
to keep an eye on these joints and nip up if required before any
weep develops into a leak.

Very helpful, thanks.


The Firebird Combi is a decent unit but
the heat exchanger requires monitoring. In hard water areas it
sometimes pinholes between the domestic and the sealed system
side, however this is not a regular event by any means.

John


That's interesting, because I've got a slow leak somewhere. I
suspect the boiler was put together by an amateur (FSVO) because
pretty well every joint on it and the central heating circuit has
leaked at some point since I moved in. I presume the only way to
test it is to disconnect the hot water side and wait a long time,
or
is it better to take it off and pressurise it in some way? I'll
have
to check that when I redo it. It's a soft water area, however.


Further to this problem, the next time a heat exchanger union leaked
I dismantled the relevant piping. With 3 unions coplanar, the
fourth was displaced 3 cm axially and 1cm radially, obviously too
much to be taken up by adjusting the other joint on the pipe.
Adjusting a straight bit of pipework to one of the pumps largely
rectified it and I could reassemble it with reduced asymmetrical
forces on the unions and new, hopefully not so soft, washers. So
far, so good.

Thanks to all for the help.


--
Percy Picacity